Objective: To investigate the level of agreement between patients, mothers, fathers, and physicians in rating pain intensity in juvenile idiopathic arthritis (JIA), and to identify factors explaining discrepancies between raters.
Methods: Ninety-four children with JIA and their mothers and fathers were asked to rate independently the intensity of present pain and pain in the previous week on a visual analog scale. The physicians rated pain intensity after physical examination. Agreement between raters was determined using intraclass correlation coefficient and Bland and Altman method. Correlations of explanatory variables with discordance in rating pain intensity were determined by univariate and multivariate analyses. Explanatory variables included sex, age, JIA category, disease duration, results of study ratings, joint inflammation measures, and erythrocyte sedimentation rate.
Results: Agreement in rating present pain was moderate between children and mothers, but was poor between children and fathers and children and physicians. The agreement in rating pain in the previous week was moderate between children and mothers and children and fathers. Mother-father agreement was good. Parents and physicians agreed at a moderate level. In multiple regression analyses, only intensity of present pain was significantly associated with discordance within child-mother, child-father, and child-physician dyads.
Conclusion: Children's ratings of pain were only in moderate agreement with those of their parents and were in poor agreement with those of the physicians, whereas the father and mothers agreed at a good level. The intensity of pain was the strongest determinant of discordance between children and other raters.